Just to confirm. We just upgraded from 4.2.7.SP1 to 4.3.0.CR1 and I notice that my container (JBoss Fuse 6) suddenly don't like Hibernate anymore. The reason seems to be a new dependency to Java 7. Is this intentional?

The code in question that breaks Java 6 is in org.hibernate.osgi.OsgiClassLoader. The method "getClassLoadingLock" is not available in Java 6, but it is in Java 7.